FIG. 1 is a perspective view of a reamer for implant surgery according to a conventional invention, and FIG. 2 is a front view of the reamer for implant surgery according to the conventional invention. As shown in FIGS. 1 and 2, the reamer for implant surgery according to the conventional invention includes: a protruding face 121 formed in such a manner as to upwardly upheave a partial surface including an outer circumference of a cutting part 1 out of the entire top surface of the cutting part 1 to form a stepped jaw 122; a depressed face 111 formed in such a manner as to depress a partial surface out of the entire top surface of the cutting part 1 according to the formation of the protruding face 121, on the contrary to the protruding face 121; a cut edge 120 formed on a connected portion between the stepped jaw 122 and the protruding face 121; and a discharge path 140 formed between the side surfaces of the depressed face 111 and the protruding face 121, wherein the depressed face 111 is upwardly slanted as it goes toward the front side of the stepped jaw 122 and becomes narrowed in width as it goes toward the end of the upper portion thereof so as to form a cutting front end portion 110 at the upper end thereof.
Moreover, the depressed face 111 and the protruding face 121 of the cutting part 1 form a tapered portion 130 along the outer peripheries thereof so as to form an initial inclined edge 131 at the boundary portion between the discharge path 140 and the outer periphery of the depressed face 111 and so as to form a final inclined edge 132 at the boundary portion between the discharge path 140 and the outer periphery of the protruding face 121, wherein the tapered portion 130 is decreased in an angle (θ) with respect to the axis of the reamer and is increased in width of the tapered portion 130 as it is rotated from the initial inclined edge 18 toward the final inclined edge 19.
The above-mentioned reamer for implant surgery according to the conventional invention is disclosed in Korean Patent No. 10-0792649 which was filed to the Korean Intellectual Property Office by the same inventor as the present invention.
However, the reamer for implant surgery according to the conventional invention has five disadvantages. First, as shown in FIG. 1, because the reamer for implant surgery according to the conventional invention includes the cutting front end portion 110 of which front end is sharp and which is eccentric based on a rotation central axis (C), it is difficult to carry out a centrum rotation on the rotation central axis (C) when the cutting part 1 is rotated.
That is, when rotary power is applied to the cutting part 1, power to rotate around the cutting front end portion 110 of which front end is sharp is generated, and hence, it is difficult to carry out the centrum rotation because there occurs a rotation interference relative to the rotation central axis (C) of the cutting part 1 which became the standard. Therefore, when a user works using the conventional reamer for implant surgery as shown in FIG. 1, it must be rotated at low speed, and the rotation center must be first formed before the user uses the reamer in order to secure the centrum rotation of the cutting part 1.
Second, the conventional reamer is very low in cutting efficiency because it has one cutting front end portion 110, one cut edge 120 and one initial inclined edge 131. Third, the conventional reamer is low in cutting efficiency, there is a high probability of generating friction heat during the high speed rotation of the reamer because a contact area between the reamer and the bone is wide, and the reamer cannot carry out high speed rotation because there is a risk of bone heat necrosis by friction heat.
Fourth, because a passage through which physiological saline which can cool friction heat between the reamer and the bone during the rotation of the reamer can arrive at the cutting part is small, it is difficult to make the physiological saline arrive at the cutting part. Fifth, the conventional reamer must stop operation and frequently remove splinters of the bone in order to keep the cutting efficiency of the cutting part because a mooring space of the splinters of the bone generated by rotation of the reamer is small and it is difficult to discharge the splinters of the bone by rotation.
In the meantime, “AHN, Sang-Hoon” who is the applicant and the inventor of the present invention has done a lot of efforts to solve problems of the conventional reamer for implant surgery and to improve performance of the reamer, and as a result, and has contributed to industrial development by inventing a “reamer for implant surgery” disclosed in Korean Patent No. 10-0630304 and a “reamer for operating implant maxillary sinus” disclosed in Korean Patent No. 10-0792649.